When a thin-film layer is formed on the surface of a substrate, the thin-film layer on the periphery of the substrate sometimes is thicker than the thin-film layer formed in the inner part of the substrate. Or sometimes the thin-film layer reaches the reverse side of the substrate.
For example, Patent Document 1 discloses an apparatus that forms a thin-film layer that can be used for a chemical filter or for organic EL wherein the apparatus is designed to prevent a thin-film layer having an uneven thickness from being formed on the periphery of the substrate because of dripping of a liquid during manufacturing, for example, by an immersion dipping, which is one of the wet processes. But to form a thin-film layer that has a completely even thickness is difficult. Therefore, after the thin-film layer is formed in accord with the accuracy in thickness that is required of the thin-film layer formed on the substrate, preferably the thin-film layer is treated by a process that makes the thin film have an even thickness.
Also, a thin-film solar battery panel (hereafter, “solar battery panel”) is manufactured by having a layer of transparent electrodes, a semi-conductive layer, a metal layer, etc., laminated on the surface of the substrate of glass, etc. The laminating process is carried out, for example, by a vapor phase reaction, whereby sometimes the thin-film layer goes around the peripheral edge of the substrate and reaches its reverse surface. A solar battery module needs an insulating characteristic. So, to give this characteristic to the solar battery, to remove the thin-film layer on the periphery of the substrate of the thin-film solar battery by a blasting treatment is proposed (Patent Document 2).
In the process of removing the thin-film layer on the periphery of the substrate by the blasting treatment, sometimes the sprayed particles (abrasives), and the dust that is the particles of the thin-film layer, etc., and that is abraded and removed, remain on the solar battery panel. A method of removing the thin-film layer on the periphery of the substrate is proposed in Reference 3 wherein no sprayed particles or dust remain on the substrate.